Systems for dispensing fuel into vehicle fuel tanks are in common use. These systems typically include a nozzle connected to a pump by a fuel delivery hose. Such nozzles are manually operable and include a spout to be inserted in the fill tube of the vehicle fuel tank. These nozzles include valves under the control of the operator for dispensing fuel through the nozzle into the vehicle tank until the tank is full. Usually a shut-off mechanism is provided and disconnects the manually operable valve lever from the valve when the fuel tank is filled with fuel. Such shut-off mechanisms are typically responsive to fuel flow through the nozzle by a venturi which creates a partial vacuum in a shut-off tube that extends to the outer end of the spout.
Heretofore, shut-off mechanisms for disconnecting the manually operable lever from the main valve have employed complicated valves and linkages which are subject to malfunctions. In addition, such mechanisms are expensive and difficult to assemble and maintain.
Environmental concerns have dictated that fuel dispensing systems include means for recovering vapors from the vehicle tank as such vapors are dispelled by the rising level of fuel being dispensed into the vehicle tank. Examples of such vapor recovery nozzles are disclosed in U.S. Pat. Nos. 4,351,375; 4,429,725; and 4,649,969. These vapor recovery nozzles suffer from several deficiencies and disadvantages. Firstly, all of these nozzles have the inlet into the vapor recovery passageways located either externally of the fill opening into the vehicle tank as disclosed in U.S. Pat. No. 4,649,969 or closely adjacent to the outer end of the spout of the nozzle as disclosed in the other two patents. With the inlet opening into the vapor recovery passageway located closely adjacent the outer end of the nozzle, such inlet opening is spaced inwardly of the fill tube of the vehicle tank a considerable distance from the restrictor plate in that fill tube. Accordingly, considerable vapors can accumulate between the inlet opening of the vapor recovery tube and the restrictor plate in the fill tube of the vehicle tank.
Secondly, the vapor recovery fuel dispensing nozzles disclosed in U.S. Pat. Nos. 4,351,375 and 4,429,725 have the vapor recovery passageways extending into the mounting means for mounting the spout on the main body of the nozzles. Accordingly, the vapor recovery passageway must pass through the mounting means for the nozzle spout and invariably such passageway follows a tortuous path and is fairly restricted in area. Such a restricted passageway limits the volume of vapors that can be recovered.
With the forgoing in mind, it is an object of the present invention to provide a fuel dispensing and vapor recovery nozzle having a vapor recovery passageway in the spout of the nozzle with at least one inlet opening which can recover substantially all vapors from the vehicle fuel tank.
It is a more specific object of the present invention to provide a vapor passageway through the nozzle which is relatively straight and devoid of constrictions or substantial flow impeding changes in direction.
It is a further more specific object of the present invention to provide an improved shut-off mechanism that is simple in construction and efficient in operation and easy to install and maintain.